At present, as the resolution of a camera for a mobile terminal becomes higher, pictures photographed by the camera may become larger and larger in size. However, considering portability, the screen of the mobile terminal may generally be not more than 6 inches, so some details may not be viewed clearly when these large pictures are displayed on the screen. Consequently, these pictures may need to be zoomed-in for viewing. In the prior art, zooming-in a picture on a mobile terminal may generally be realized by sliding two fingers on the touch screen in opposite directions, but this zoom-in method may be difficult to use to ensure zoom-in precision. Moreover, as the slide operations of two fingers may not be consistent every time, it may often be difficult to achieve a purpose of zooming-in a same region for two times.
Therefore, further improvements and developments are needed in the prior art.